Steam or boil the potatoes for 10-15 minutes, or until just tender (pierce with the point of a small sharp knife—if the potato comes away easily it is ready). Drain well and return to the pan. Stir over medium heat to remove excess moisture. Mash roughly, leaving a few small lumps. Allow the mash to cool slightly.

Melt the butter in a pan, then fry the onion over medium heat for 2-3 minutes, or until soft but not browned.

Drain the salmon, remove any dark skin and bones, then flake roughly with a fork in a large bowl. Add the potato mash, onion, egg, lemon juice and parsley. Mix together well (the mixture should still have a few small lumps and will be a little soft).

Form the mixture into eight patties. Place the flour and breadcrumbs into two shallow dishes or plates. Combine the beaten egg and milk in a shallow dish or bowl. Coat the patties lightly in the flour, then in the egg and milk. Finally, coat with the breadcrumbs. Place on a baking tray covered with baking paper. Reshape the patties if necessary, then refrigerate for 30 minutes to firm up the patties.

Heat 3 tablespoons of oil in a frying pan and cook the patties over medium heat, in two batches, for 4 minutes each side, or until golden brown, adding more oil as needed. Remove the patties from the pan and drain on paper towels.